https://techcrunch.com/2023/04/17/spacex-transitions-todays-starship-orbital-flight-test-to-wet-dress-rehearsal/

SpaceX has just announced that today’s orbital flight test attempt of the Starship launch system will now be a wet dress rehearsal, due to a frozen pressure valve.

That means countdown will conclude at T-10 seconds. The news came at around T-8 minutes and countdown. It will take at least 48 hours for the company to recycle the vehicle, meaning another launch attempt won’t take place until Wednesday morning at the earliest.